[thirdparty/u-boot.git] / drivers / timer / nomadik-mtu-timer.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2019 Stephan Gerhold <stephan@gerhold.net>
 *
 * Based on arch/arm/cpu/armv7/u8500/timer.c:
 * Copyright (C) 2010 Linaro Limited
 * John Rigby <john.rigby@linaro.org>
 *
 * Based on Linux kernel source and internal ST-Ericsson U-Boot source:
 * Copyright (C) 2009 Alessandro Rubini
 * Copyright (C) 2010 ST-Ericsson
 * Copyright (C) 2010 Linus Walleij for ST-Ericsson
 */

#include <common.h>
#include <dm.h>
#include <timer.h>
#include <asm/io.h>
#include <linux/bitops.h>

#define MTU_NUM_TIMERS		4

/* The timers */
struct nomadik_mtu_timer_regs {
	u32 lr;		/* Load register */
	u32 cv;		/* Current value */
	u32 cr;		/* Control register */
	u32 bglr;	/* Background load register */
};

/* The MTU that contains the timers */
struct nomadik_mtu_regs {
	u32 imsc;	/* Interrupt mask set/clear */
	u32 ris;	/* Raw interrupt status */
	u32 mis;	/* Masked interrupt status */
	u32 icr;	/* Interrupt clear register */

	struct nomadik_mtu_timer_regs timers[MTU_NUM_TIMERS];
};

/* Bits for the control register */
#define MTU_CR_ONESHOT		BIT(0)	/* if 0 = wraps reloading from BGLR */
#define MTU_CR_32BITS		BIT(1)	/* if 0 = 16-bit counter */

#define MTU_CR_PRESCALE_SHIFT	2
#define MTU_CR_PRESCALE_1	(0 << MTU_CR_PRESCALE_SHIFT)
#define MTU_CR_PRESCALE_16	(1 << MTU_CR_PRESCALE_SHIFT)
#define MTU_CR_PRESCALE_256	(2 << MTU_CR_PRESCALE_SHIFT)

#define MTU_CR_PERIODIC		BIT(6)	/* if 0 = free-running */
#define MTU_CR_ENABLE		BIT(7)

struct nomadik_mtu_priv {
	struct nomadik_mtu_timer_regs *timer;
};

static u64 nomadik_mtu_get_count(struct udevice *dev)
{
	struct nomadik_mtu_priv *priv = dev_get_priv(dev);

	/* Decrementing counter: invert the value */
	return timer_conv_64(~readl(&priv->timer->cv));
}

static int nomadik_mtu_probe(struct udevice *dev)
{
	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
	struct nomadik_mtu_priv *priv = dev_get_priv(dev);
	struct nomadik_mtu_regs *mtu;
	u32 prescale;

	mtu = dev_read_addr_ptr(dev);
	if (!mtu)
		return -EINVAL;
	priv->timer = mtu->timers; /* Use first timer */

	if (!uc_priv->clock_rate)
		return -EINVAL;

	/* Use divide-by-16 counter if tick rate is more than 32 MHz */
	if (uc_priv->clock_rate > 32000000) {
		uc_priv->clock_rate /= 16;
		prescale = MTU_CR_PRESCALE_16;
	} else {
		prescale = MTU_CR_PRESCALE_1;
	}

	/* Configure a free-running, auto-wrap counter with selected prescale */
	writel(MTU_CR_ENABLE | prescale | MTU_CR_32BITS, &priv->timer->cr);

	return 0;
}

static const struct timer_ops nomadik_mtu_ops = {
	.get_count = nomadik_mtu_get_count,
};

static const struct udevice_id nomadik_mtu_ids[] = {
	{ .compatible = "st,nomadik-mtu" },
	{}
};

U_BOOT_DRIVER(nomadik_mtu) = {
	.name = "nomadik_mtu",
	.id = UCLASS_TIMER,
	.of_match = nomadik_mtu_ids,
	.priv_auto	= sizeof(struct nomadik_mtu_priv),
	.probe = nomadik_mtu_probe,
	.ops = &nomadik_mtu_ops,
};
Commit	Line	Data
057b6139 SG	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Copyright (C) 2019 Stephan Gerhold <stephan@gerhold.net>
	4	*
	5	* Based on arch/arm/cpu/armv7/u8500/timer.c:
	6	* Copyright (C) 2010 Linaro Limited
	7	* John Rigby <john.rigby@linaro.org>
	8	*
	9	* Based on Linux kernel source and internal ST-Ericsson U-Boot source:
	10	* Copyright (C) 2009 Alessandro Rubini
	11	* Copyright (C) 2010 ST-Ericsson
	12	* Copyright (C) 2010 Linus Walleij for ST-Ericsson
	13	*/
	14
d678a59d	15	#include <common.h>
057b6139 SG	16	#include <dm.h>
	17	#include <timer.h>
	18	#include <asm/io.h>
cd93d625	19	#include <linux/bitops.h>
057b6139 SG	20
	21	#define MTU_NUM_TIMERS 4
	22
	23	/* The timers */
	24	struct nomadik_mtu_timer_regs {
	25	u32 lr; /* Load register */
	26	u32 cv; /* Current value */
	27	u32 cr; /* Control register */
	28	u32 bglr; /* Background load register */
	29	};
	30
	31	/* The MTU that contains the timers */
	32	struct nomadik_mtu_regs {
	33	u32 imsc; /* Interrupt mask set/clear */
	34	u32 ris; /* Raw interrupt status */
	35	u32 mis; /* Masked interrupt status */
	36	u32 icr; /* Interrupt clear register */
	37
	38	struct nomadik_mtu_timer_regs timers[MTU_NUM_TIMERS];
	39	};
	40
	41	/* Bits for the control register */
	42	#define MTU_CR_ONESHOT BIT(0) /* if 0 = wraps reloading from BGLR */
	43	#define MTU_CR_32BITS BIT(1) /* if 0 = 16-bit counter */
	44
	45	#define MTU_CR_PRESCALE_SHIFT 2
	46	#define MTU_CR_PRESCALE_1 (0 << MTU_CR_PRESCALE_SHIFT)
	47	#define MTU_CR_PRESCALE_16 (1 << MTU_CR_PRESCALE_SHIFT)
	48	#define MTU_CR_PRESCALE_256 (2 << MTU_CR_PRESCALE_SHIFT)
	49
	50	#define MTU_CR_PERIODIC BIT(6) /* if 0 = free-running */
	51	#define MTU_CR_ENABLE BIT(7)
	52
	53	struct nomadik_mtu_priv {
	54	struct nomadik_mtu_timer_regs *timer;
	55	};
	56
8af7bb91	57	static u64 nomadik_mtu_get_count(struct udevice *dev)
057b6139 SG	58	{
	59	struct nomadik_mtu_priv *priv = dev_get_priv(dev);
	60
	61	/* Decrementing counter: invert the value */
8af7bb91	62	return timer_conv_64(~readl(&priv->timer->cv));
057b6139 SG	63	}
	64
	65	static int nomadik_mtu_probe(struct udevice *dev)
	66	{
	67	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
	68	struct nomadik_mtu_priv *priv = dev_get_priv(dev);
	69	struct nomadik_mtu_regs *mtu;
057b6139 SG	70	u32 prescale;
057b6139 SG	71
0e6956cc SG	72	mtu = dev_read_addr_ptr(dev);
0e6956cc SG	73	if (!mtu)
057b6139	74	return -EINVAL;
057b6139 SG	75	priv->timer = mtu->timers; /* Use first timer */
	76
	77	if (!uc_priv->clock_rate)
	78	return -EINVAL;
	79
	80	/* Use divide-by-16 counter if tick rate is more than 32 MHz */
	81	if (uc_priv->clock_rate > 32000000) {
	82	uc_priv->clock_rate /= 16;
	83	prescale = MTU_CR_PRESCALE_16;
	84	} else {
	85	prescale = MTU_CR_PRESCALE_1;
	86	}
	87
	88	/* Configure a free-running, auto-wrap counter with selected prescale */
	89	writel(MTU_CR_ENABLE \| prescale \| MTU_CR_32BITS, &priv->timer->cr);
	90
	91	return 0;
	92	}
	93
	94	static const struct timer_ops nomadik_mtu_ops = {
	95	.get_count = nomadik_mtu_get_count,
	96	};
	97
	98	static const struct udevice_id nomadik_mtu_ids[] = {
	99	{ .compatible = "st,nomadik-mtu" },
	100	{}
	101	};
	102
	103	U_BOOT_DRIVER(nomadik_mtu) = {
	104	.name = "nomadik_mtu",
	105	.id = UCLASS_TIMER,
	106	.of_match = nomadik_mtu_ids,
41575d8e	107	.priv_auto = sizeof(struct nomadik_mtu_priv),
057b6139 SG	108	.probe = nomadik_mtu_probe,
	109	.ops = &nomadik_mtu_ops,
	110	};